Toilet tank



FIG. 1 is a front, top, right side perspective view of a toilet tank showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a rear, bottom, right side, perspective view thereof.

Broken lines shown in the figures depict portions of the toilet tank that form no part of the claimed design. 

CLAIM I claim the ornamental design for a toilet tank, shown and described. 